The complexity of some airports, the increase in air traffic, the existence of installations that are often ill-suited to airplanes which are increasingly large and numerous, create traffic difficulties on the runways and the taxiways of the airports, often leading to extended taxiing times, sometimes more or less serious incidents, and, unfortunately, also accidents.
In this context, an increasingly high number of “runway incursions” are observed, involving situations where an unauthorized airplane penetrates onto the runway which is used at the same time in the proper way by another airplane, to land or take off. Such a runway incursion is very dangerous, since it endangers the lives of the occupants of both airplanes.
For safety reasons, it is therefore important, not to say imperative, for each pilot to be able to monitor the immediate environment of his airplane as effectively as possible and, if necessary, be informed of any runway incursion (or any risk of incursion).
An article by Beskenis, Green, Hyer and Johnson entitled “Integrated Display System for Low Visibility Landing and Surface Operations”, published in the publication “NASA Langley Technical Report”, July 1998, NAS/CR-1998-208446, discloses a display system which is on board an airplane, to assist the pilot of the airplane with ground maneuvers. To this end, this display system comprises, in particular, display means for presenting on a screen mounted in the cockpit of the airplane, a map of the airport showing the runways, the taxiways and the various buildings, and the position of the airplane and the traffic that exists at that airport.
This display system therefore implements an airport navigation function which makes it possible to locate the position of the airplane on an electronic airport map.
When navigating on the ground, air traffic controllers normally transmit to the pilot of the aircraft, orally, via a radio transmission, a succession of way points (names of taxiways and/or runways, etc.). This information helps the pilot guide the airplane at the airport. However, in the abovementioned situation, the pilot needs to himself ensure the correlation between the information transmitted by the air traffic controllers and the onboard electronic map, on which are displayed the plan of the airport and the position of his airplane. This results in a major workload for the pilot and makes the airport navigation system open to errors of interpretation or of understanding of the oral information received.
Moreover, the frequencies, normally of VHF (Very High Frequency) type, which are used for the voice communications are often saturated, particularly at complex airports, which limits the controllers in their capacity to manage all the movements of the airplanes on the ground.
Furthermore, there are also problems of understanding and interpretation in such voice communications, particularly for the following reasons: disturbed transmission or poor reception, inability to understand (accent of the speaker, speed and/or clarity of speech), impossibility of having the information repeated on large airports, verbal phraseology not respected, etc.